As used herein, Long Wave Infrared is referred to as “LWIR” or “thermal.” As used herein, “mapping” refers to placing objects in a scene relative to other objects or elements in the scene. As an example, “that little rock is in the road next to that big rock just off the road.” As used herein, “roadway” refers to any path along which a person, animal, or vehicle may traverse.
A method using Long Wave Infrared Imaging Polarimetry for improved mapping and perception of a roadway or path and for perceiving or detecting objects is disclosed herein. The described method is not tied to any one specific polarimeter sensor architecture, and thus the method described pertains to all LWIR sensors capable of detecting the critical polarimetric signature. The method comprises recording raw image data of an area using a polarimeter to obtain polarized images of the area. The images are then corrected for non-uniformity, optical distortion, and registration in accordance with the procedure necessitated by the sensor's architecture. IR and polarization data products are computed, and the resultant data products are converted to a multi-dimensional data set for exploitation. Contrast enhancement algorithms are applied to the multi-dimensional imagery to form enhanced object images. The enhanced object images may then be displayed to a user, and/or an annunciator may announce the presence of an object. Further, the vehicle may take evasive action based upon the presence of an object in the roadway.
A standard IR camera gives information about an IR signature (i.e., how bright a target looks), spatial information (i.e., where a target is in the scene), and temporal information (i.e., how the target changes in the scene from frame to frame). A polarimetric system and method as disclosed herein provides all of this information and also a polarimetric signature.